1. Field of the Invention
The present invention relates to a head suspension for a disk drive incorporated in an information processing apparatus such as a personal computer.
2. Description of Related Art
Small-sized, precision information devices are rapidly advancing, and for use with such devices, needs for micro-actuators capable of conducting positioning control for very small distances are increasing. Such micro-actuators are highly needed by, for example, optical systems for correcting focuses and inclination angles, ink jet printers for controlling ink heads, and magnetic disk drives for controlling magnetic heads.
To meet the needs, the applicant of the present invention has proposed in Japanese Unexamined Patent Application Publication No. 2002-50140 a head suspension for a disk drive, including a base plate, a connection plate having a hinge thinner than the base plate, a load beam provided with a flexure, and a piezoelectric actuator composed of a pair of piezoelectric elements.
This related art employs a dual actuator system that involves, for a precise positioning purpose, a voice coil motor and the piezoelectric actuator having two piezoelectric elements made of, for example, PZT (lead zirconate titanate). The piezoelectric actuator in the dual actuator system minutely moves a front end of the load beam in a widthwise direction (sway direction) of the head suspension.
Compared with a single actuator system employing only the voice coil motor, the dual actuator system employing the voice coil motor and piezoelectric actuator is capable of more precisely positioning a magnetic head attached to a front end of the head suspension.
In the head suspension of the dual actuator system, the piezoelectric actuator is arranged in an opening formed in a piezoelectric element attaching part prepared on, for example, the base plate. This type of arrangement is disclosed in Japanese Unexamined Patent Application Publication No. 2001-307442.
The applicant of the present invention has proposed in the Japanese Unexamined Patent Application Publication No. 2002-50140 a technique of supporting an electrode of a piezoelectric element with a support that is formed at an opening formed in the base plate of the head suspension. The applicant of the present invention has also proposed in Japanese Unexamined Patent Application Publication No. 2002-184140 a technique of supporting a pair of piezoelectric elements with a support that has a base end, a front end, and a bridge extending along a center line of a head suspension to connect the base end and front end to each other. The base and front ends of the support hold front and rear ends of the piezoelectric elements that are arranged on each side of the bridge of the support.
These related arts involve many parts to complicate the structure for supporting the piezoelectric element. As a result, the head suspensions according to the related arts complicate manufacturing processes and make it difficult to secure assembling accuracy.